/* Real Analytics 101 — Design System
   Navy / Gold / Black on White — Editorial (HBR / McKinsey) */

:root {
  --navy: #0A1F3D;
  --navy-ink: #081830;
  --gold: #B8901F;
  --gold-light: #D4AF37;
  --ink: #111111;
  --body-text: #333333;
  --muted: #6B7280;
  --rule: #E4E1D8;
  --paper: #FFFFFF;
  --paper-tint: #FBFAF8;
  --serif: 'Source Serif 4', Georgia, 'Times New Roman', serif;
  --sans: 'Inter', -apple-system, BlinkMacSystemFont, 'Segoe UI', sans-serif;
  --max: 1180px;
}

* { box-sizing: border-box; }

html { scroll-behavior: smooth; }

body {
  margin: 0;
  font-family: var(--sans);
  color: var(--ink);
  background: var(--paper);
  -webkit-font-smoothing: antialiased;
}

img { max-width: 100%; display: block; }

a { color: inherit; }

.wrap { max-width: var(--max); margin: 0 auto; padding: 0 24px; }

/* ---------- Masthead ---------- */
.masthead {
  border-bottom: 1px solid var(--rule);
  position: sticky;
  top: 0;
  background: rgba(255,255,255,0.97);
  backdrop-filter: blur(4px);
  z-index: 50;
}
.masthead .bar {
  display: flex;
  align-items: center;
  justify-content: space-between;
  height: 76px;
}
.brand {
  display: flex;
  align-items: center;
  gap: 12px;
  text-decoration: none;
  color: var(--ink);
}
.brand .mark {
  width: 34px; height: 34px;
  background: var(--navy);
  display: flex; align-items: center; justify-content: center;
  color: var(--gold);
  font-family: var(--serif);
  font-weight: 700;
  font-size: 18px;
  flex-shrink: 0;
}
.brand .name {
  font-family: var(--serif);
  font-weight: 700;
  font-size: 19px;
  letter-spacing: -0.01em;
  white-space: nowrap;
}
.brand .name span { color: var(--gold); }

nav.primary {
  display: flex;
  gap: 30px;
  align-items: center;
}
nav.primary a {
  text-decoration: none;
  font-size: 14px;
  font-weight: 500;
  color: var(--ink);
}
nav.primary a:hover { color: var(--navy); border-bottom: 2px solid var(--gold); }

.btn-primary {
  background: var(--navy);
  color: #fff !important;
  padding: 10px 20px;
  font-size: 13px;
  font-weight: 600;
  text-decoration: none;
  letter-spacing: 0.03em;
  display: inline-block;
  border: none;
  cursor: pointer;
}
.btn-primary:hover { background: var(--navy-ink); }

.btn-outline {
  border: 1px solid var(--navy);
  color: var(--navy) !important;
  padding: 13px 26px;
  font-size: 14px;
  font-weight: 600;
  text-decoration: none;
  letter-spacing: 0.02em;
  display: inline-block;
}

.nav-toggle {
  display: none;
  background: none; border: none; cursor: pointer;
}
.mobile-menu {
  display: none;
  border-top: 1px solid var(--rule);
  padding: 16px 24px 24px;
  flex-direction: column;
  gap: 16px;
}
.mobile-menu a { text-decoration: none; color: var(--ink); font-size: 15px; font-weight: 500; }
.mobile-menu.open { display: flex; }

/* ---------- Kicker ---------- */
.kicker {
  display: flex; align-items: center; gap: 10px;
  font-size: 12px; letter-spacing: 0.14em; text-transform: uppercase;
  color: var(--navy); font-weight: 600;
}
.kicker::before { content: ""; width: 22px; height: 2px; background: var(--gold); display: inline-block; }
.kicker.on-dark { color: var(--gold); }
.kicker.on-dark::before { background: var(--gold); }

/* ---------- Hero (homepage) ---------- */
.hero {
  padding: 72px 0 56px;
  display: grid;
  grid-template-columns: 1.3fr 1fr;
  gap: 56px;
  align-items: end;
}
.hero h1 {
  font-family: var(--serif);
  font-size: clamp(2.2rem, 4.2vw, 3.6rem);
  line-height: 1.08;
  font-weight: 700;
  margin: 22px 0 24px;
  letter-spacing: -0.015em;
  color: var(--navy);
}
.hero .lede {
  font-size: 18px;
  line-height: 1.6;
  color: var(--body-text);
  max-width: 520px;
  margin-bottom: 32px;
}
.hero .actions { display: flex; gap: 16px; flex-wrap: wrap; }
.hero .actions .btn-primary { display: inline-flex; align-items: center; gap: 8px; }

.featured-callout {
  border-left: 3px solid var(--gold);
  padding-left: 24px;
}
.featured-callout .eyebrow {
  font-size: 11px; letter-spacing: 0.14em; text-transform: uppercase;
  color: var(--gold); font-weight: 700; margin-bottom: 14px;
}
.featured-callout h3 {
  font-family: var(--serif); font-size: 22px; line-height: 1.3; color: var(--navy);
  margin: 0 0 12px; font-weight: 700;
}
.featured-callout p { font-size: 14.5px; line-height: 1.6; color: #4A4A4A; margin-bottom: 16px; }
.featured-callout a {
  font-size: 13px; font-weight: 700; color: var(--navy); text-decoration: none;
  border-bottom: 1px solid var(--gold); padding-bottom: 2px;
}

/* ---------- Pillars ---------- */
.pillars-section { border-top: 1px solid var(--rule); border-bottom: 1px solid var(--rule); background: var(--paper-tint); }
.pillars-grid { display: grid; grid-template-columns: repeat(3,1fr); padding: 56px 0; }
.pillar-item { padding: 8px 32px; border-left: 1px solid var(--rule); }
.pillar-item:first-child { border-left: none; }
.pillar-item .label { font-family: var(--serif); font-size: 20px; font-weight: 700; color: var(--navy); margin-bottom: 12px; }
.pillar-item p { font-size: 14.5px; line-height: 1.6; color: #4A4A4A; margin-bottom: 18px; }
.pillar-item a.more { font-size: 13px; font-weight: 700; color: var(--gold); text-decoration: none; }

/* ---------- Section heading ---------- */
.section-head {
  display: flex; justify-content: space-between; align-items: baseline;
  flex-wrap: wrap; gap: 12px; margin-bottom: 8px;
}
.section-head a.view-all { font-size: 13px; font-weight: 600; color: var(--navy); text-decoration: none; }
.section-title {
  font-family: var(--serif); font-size: 30px; font-weight: 700; color: var(--navy);
  margin: 18px 0 40px;
}

/* ---------- Card grids ---------- */
.card-grid { display: grid; grid-template-columns: repeat(3,1fr); gap: 36px 32px; }
.card {
  text-decoration: none; color: inherit; display: block;
  border-top: 2px solid var(--navy); padding-top: 16px;
}
.card .kind { font-size: 11px; font-weight: 700; letter-spacing: 0.1em; text-transform: uppercase; color: var(--gold); margin-bottom: 10px; }
.card .title { font-family: var(--serif); font-size: 18px; font-weight: 700; line-height: 1.35; color: var(--ink); }

/* ---------- Dark band (blog strip) ---------- */
.dark-band { background: var(--navy); color: #fff; padding: 64px 0; }
.dark-grid { display: grid; grid-template-columns: repeat(3,1fr); gap: 32px; }
.dark-grid a {
  text-decoration: none; color: #fff;
  border-left: 1px solid rgba(255,255,255,0.2); padding-left: 20px;
}
.dark-grid .meta { font-size: 11px; letter-spacing: 0.08em; text-transform: uppercase; color: rgba(255,255,255,0.55); margin-bottom: 10px; font-weight: 600; }
.dark-grid .title { font-family: var(--serif); font-size: 17px; line-height: 1.4; font-weight: 700; }

/* ---------- Footer ---------- */
footer.site-footer { padding: 32px 0; border-top: 1px solid var(--rule); margin-top: 40px; }
footer.site-footer .row { display: flex; justify-content: space-between; align-items: center; flex-wrap: wrap; gap: 12px; }
footer.site-footer .copyright { font-size: 13px; color: #666; }
footer.site-footer .links { display: flex; gap: 24px; }
footer.site-footer .links a { font-size: 13px; color: #666; text-decoration: none; }
footer.site-footer .links a:hover { color: var(--navy); }

/* ---------- Article / content page ---------- */
.article-header { padding: 56px 0 32px; border-bottom: 1px solid var(--rule); }
.article-header .kind-tag {
  font-size: 12px; font-weight: 700; letter-spacing: 0.1em; text-transform: uppercase;
  color: var(--gold); margin-bottom: 16px;
}
.article-header h1 {
  font-family: var(--serif); font-size: clamp(1.9rem, 3.4vw, 2.7rem);
  line-height: 1.15; color: var(--navy); font-weight: 700; margin: 0 0 16px; letter-spacing: -0.01em;
}
.article-header .dek { font-size: 17px; color: var(--muted); max-width: 700px; line-height: 1.55; }

.article-body { padding: 48px 0 80px; max-width: 760px; margin: 0 auto; }
.article-body h2 {
  font-family: var(--serif); color: var(--navy); font-size: 26px; font-weight: 700;
  margin: 44px 0 18px; letter-spacing: -0.01em;
}
.article-body h3 {
  font-family: var(--serif); color: var(--navy); font-size: 20px; font-weight: 700;
  margin: 32px 0 14px;
}
.article-body p { font-size: 17px; line-height: 1.75; color: var(--body-text); margin: 0 0 22px; }
.article-body ul, .article-body ol { font-size: 17px; line-height: 1.75; color: var(--body-text); margin: 0 0 22px; padding-left: 26px; }
.article-body li { margin-bottom: 8px; }
.article-body figure { margin: 32px 0; }
.article-body figure img { border: 1px solid var(--rule); }
.article-body figcaption { font-size: 13px; color: var(--muted); margin-top: 10px; text-align: center; }
.article-body blockquote {
  border-left: 3px solid var(--gold); margin: 32px 0; padding: 4px 0 4px 24px;
  font-family: var(--serif); font-size: 20px; font-style: italic; color: var(--navy); line-height: 1.5;
}
.article-body .callout {
  border-left: 3px solid var(--gold); background: var(--paper-tint);
  padding: 20px 24px; margin: 32px 0; font-size: 16px; color: var(--navy); font-weight: 600; line-height: 1.6;
}

.article-nav {
  max-width: 760px; margin: 0 auto; padding: 0 0 64px;
  display: flex; justify-content: space-between; gap: 16px; flex-wrap: wrap;
  border-top: 1px solid var(--rule); padding-top: 32px;
}
.article-nav a {
  font-size: 13px; font-weight: 700; color: var(--navy); text-decoration: none;
  display: inline-flex; align-items: center; gap: 6px;
}

/* ---------- Listing pages (Insights hub / Blog) ---------- */
.listing-header { padding: 64px 0 32px; }
.listing-header h1 { font-family: var(--serif); font-size: clamp(2rem,4vw,2.8rem); color: var(--navy); margin: 18px 0 16px; }
.listing-header p { font-size: 17px; color: var(--muted); max-width: 640px; line-height: 1.6; }

.filter-groups { padding: 8px 0 48px; }
.filter-group + .filter-group { margin-top: 56px; }
.filter-group h2 { font-family: var(--serif); font-size: 22px; color: var(--navy); border-bottom: 1px solid var(--rule); padding-bottom: 14px; margin-bottom: 28px; }

/* ---------- Simple content page (contact/glossary/etc) ---------- */
.simple-page { max-width: 760px; margin: 0 auto; padding: 64px 0 80px; }
.simple-page h1 { font-family: var(--serif); font-size: clamp(1.9rem,3.4vw,2.6rem); color: var(--navy); margin-bottom: 24px; }
.simple-page h2 { font-family: var(--serif); font-size: 22px; color: var(--navy); margin: 36px 0 14px; }
.simple-page p, .simple-page li { font-size: 16px; line-height: 1.75; color: var(--body-text); }
.simple-page ul { padding-left: 22px; }

.contact-grid { display: grid; grid-template-columns: 1fr 1fr; gap: 48px; margin-top: 32px; }
.contact-form label { display: block; font-size: 13px; font-weight: 600; color: var(--navy); margin: 18px 0 6px; text-transform: uppercase; letter-spacing: 0.05em; }
.contact-form input, .contact-form textarea {
  width: 100%; border: 1px solid var(--rule); padding: 12px 14px; font-family: var(--sans); font-size: 15px;
}
.contact-form textarea { min-height: 140px; resize: vertical; }
.contact-form button { margin-top: 24px; }

.glossary-term { border-top: 1px solid var(--rule); padding: 20px 0; }
.glossary-term dt { font-family: var(--serif); font-weight: 700; color: var(--navy); font-size: 17px; }
.glossary-term dd { margin: 8px 0 0; color: var(--body-text); font-size: 15px; line-height: 1.6; }

.index-list { list-style: none; padding: 0; margin: 0; }
.index-list li { border-top: 1px solid var(--rule); }
.index-list a { display: flex; justify-content: space-between; padding: 16px 0; text-decoration: none; color: var(--ink); font-size: 16px; }
.index-list a:hover { color: var(--navy); }
.index-list .cat { font-size: 12px; color: var(--muted); text-transform: uppercase; letter-spacing: 0.05em; }

.archive-note {
  border: 1px solid var(--rule); background: var(--paper-tint); padding: 20px 24px; font-size: 14px; color: var(--muted); margin-bottom: 32px;
}

/* ---------- Responsive ---------- */
@media (max-width: 900px) {
  nav.primary { display: none; }
  .nav-toggle { display: flex; }
  .hero { grid-template-columns: 1fr; }
  .pillars-grid { grid-template-columns: 1fr; }
  .pillar-item { border-left: none; border-top: 1px solid var(--rule); padding: 24px 0; }
  .card-grid { grid-template-columns: 1fr; }
  .dark-grid { grid-template-columns: 1fr; gap: 24px; }
  .contact-grid { grid-template-columns: 1fr; }
}